Robust Carrier Phase Tracking in the GNSS Space-Time Anti-Jam Array Processing

Abstract

Abstract Maliciously or not, jamming is one of the most serious threats to GNSS users, since it worsens the signals’ quality and causes the receivers out of function. There are many ways for the GNSS anti-jam; among them, the space-time array processing (STAP) technology is the most effective. However, the traditional STAP introduces carrier phase bias to signals, which may decrease the precision of phase tracking or even cause unlock of the receiver tracking loop. Although plenty of algorithms are studied to solve this problem, many prerequisites are needed for them to be applied, such as the calibration of antennas or the signals’ direction. Hence, these methods cannot be widely used in the general array receivers. In this paper, the carrier phase bias correction (CPBC) algorithm is proposed for robust GNSS carrier phase tracking in the static STAP anti-jamming receivers, which does not require the intricate pre-information compared to the traditional methods. The CPBC estimates the STAP-introduced bias in the phase tracking loop and corrects it by phase shift. The simulation and two types of open-sky tests show that the CPBC effectively mitigates the phase bias with a residual error less than 8°, and it maintains the robust phase tracking in the GNSS receiver.